This was an amazing story; you did an amazing job of balancing the two rather different shows with each other in a way that it doesn't just seem like you took a few characters a dumped them in the other show.
I particularly enjoyed the way that you weren't afraid to change things up, introduce other characters and go in further depth to certain topics showed in canon.
The characters were done extremely well; they reacted in ways that I would expect, considering the differing situations they found themselves in.

Great job on this; I would have loved to see more but realise it's not likely, good luck on any future endeavours.

I have to say I'm impressed.
To be honest, I didn't expect much from this story. Both X-Men and Xiaolin Showdown are easily crossed shows, generally following 'Character becomes a mutant and magically joins the X-Men' and 'Character is secretly a Xiaolin Dragon and suddenly Shen Gong Wu appear'. I assumed that this would be some sort of combination of the two, and I guess it kind of is, but done in all the right ways.
You've done an amazing job of blending the two universes, something that not everyone can do. You're following the sequence of episodes and showing the effects of Jack living at the Institute, without making it feel like he's just tagged to the side of canon or being a Gary-Stu.
The differences feel very real. It's never made sense to me that the show collects the cast and then only deals with them, so I like that you continued adding more mutants.
I especially enjoy how Toad is written. You gave him a realistic character development from a standard delinquent stereotype, to a leader that actually cares about the people he's leading; even to the point of putting aside his personal grudges and helping the X-Men just because they're mutants.
I understand you're reasons for going on Hiatus, and I hope you can return soon to continue this story. Great Job!

update again soon when ya can

Is okay, take your time, great story man...

Well, looks like Lockheed will be trouble...

Okay, so Sunspot can score a one hit ko on him...

Yeah that works cause comic Mimic was a tad overpowered...

Damn, some mutant powers really run your life...

Well yeah it was a sad story...

Victor? Is just me or he sound a LOT like certain villain from Spiderman? He even has the same powers!

Well, looks like Jack friends will be exposed to a Wu battle...

You could have added all this answers to a real chapter...

Well is new york so... spiderman...

Well maybe Amara had problems controlling her powers so that’s why she didn’t' go to class before?

Well Jack has become really nicer, he got them a cool car for cheap...